Different sources of non-fibrous carbohydrates for lactating goats

• Ano de defesa: 2024
• Autor(a) principal: Castro, Maria Samires Martins
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa; Zootecnia
• Palavras-chave em Português: Caprinos - Alimentação e rações; Polpa seca de cítricos na nutrição animal; Sacarose na nutrição animal; Digestibilidade; Leite de cabra - Produção; CIENCIAS AGRARIAS::ZOOTECNIA::PRODUCAO ANIMAL
• Link de acesso: https://locus.ufv.br/handle/123456789/33388; https://doi.org/10.47328/ufvbbt.2024.638

Carbohydrates are the most abundant biomolecules in nature and account for 70 to 80% of ruminant diets. Among the classifications, non-fibrous carbohydrates have been commonly used to increase milk production. Thus, the objective of this study was to evaluate the effects of the use of non-fibrous carbohydrates (NFC), such as cornmeal, pre-gelatinized corn, citrus pulp and sucrose, on nutrient intake, digestibility, milk yield and composition in lactating dairy goats. Twenty-nine primiparous (11) and multiparous (18) lactating Saanen and Alpine goats (2.8 ± 0.27 kg.d-1 milk; 55.4 ± 1.8 kg body weight) were used in this study. The goats were distributed in eight pens with four animals each, with the pen being the experimental unit and the animals being the observational units, and in four diets in a 4×4 balanced double Latin square design, with four periods of 21 days each. During the first period of the experiment, three goats stopped producing milk and were removed from the experiment. The treatments were corn meal, pre-gelatinized corn, citrus pulp and sucrose, with the roughage based on corn silage, and the roughage:concentrate ratio 60:40. The diets were formulated to meet the nutritional requirements of lactating goats and were offered in four daily meals, in the same physical form. Voluntary nutrient intake, digestibility, production weighing and samples for analysis of milk composition were performed during the seven days of each collection period. We did not consider the effect of body weight, due to the short evaluation periods present in the Latin square design, which tend to hinder the variation of weight gain, not correcting errors in ruminal filling. Goats fed corn meal showed higher lignin intake and digestibility of dry matter, organic matter and fiber, and lower intake when sucrose was used. Citrus pulp also stood out for its fiber digestibility and influenced some milk components, such as fat, protein, total solids, milk fat-corrected and net lactation energy. However, milk composition showed low values when the goats were fed sucrose. Regarding the period, only fat, milk fat- corrected and net lactation energy were influenced. Regarding ingestive behavior, there was an influence of the diet for intake, being greater when the goats received corn meal and smaller when they received pre-gelatinized corn. Regarding idleness, we observed the opposite effect, being greater in the pre-gelatinized corn diet and smaller with corn meal in the diet. We suggest that citrus pulp can be used as a concentrated feed for dairy goats, without compromising nutrient intake, digestibility, milk yield and composition. However, diets with sucrose affect intake, digestibility, milk production and composition. Keywords: Citrus pulp. Digestibility. Milk production. Sucrose.